1. Identify the Half-Reactions
* Reduction (at the cathode): Na⁺(aq) + e⁻ → Na(s)
* Oxidation (at the anode): Zn(s) → Zn²⁺(aq) + 2e⁻
2. Look Up Standard Reduction Potentials
You'll need to find the standard reduction potentials (E°) for each half-reaction. These are typically found in a table of standard reduction potentials.
* Na⁺(aq) + e⁻ → Na(s) E° = -2.71 V
* Zn²⁺(aq) + 2e⁻ → Zn(s) E° = -0.76 V
3. Determine the Overall Cell Potential (E°cell)
* For the cell reaction, the reduction potential is reversed for the oxidation half-reaction. This means we will use the negative of the standard reduction potential for the zinc half-reaction.
* The overall cell potential is calculated as:
E°cell = E°(reduction) + E°(oxidation)
E°cell = -2.71 V + (+0.76 V)
E°cell = -1.95 V
Conclusion
The total reduction potential of the cell in which sodium is reduced and zinc is oxidized is -1.95 V. This negative value indicates that the reaction is not spontaneous under standard conditions.
